ISM: Phobos

Phobos sessions

Description

High resolution observation (~0.7 km / pixel) during fly-by. Circular orbit synchronized on Phobos (Phobos quasi-synchroneous orbit), the spacecraft is depointed to follow Phobos.
The telemetry file contains two sessions: first a single-pixel track, then an image-cube. Intermediate calibration sessions include several series of 10 spectra of Phobos, that are not calibrated (see this page for details).

Observations

Name	Date	Spectra	Window size	Phase angle	Solar Meridian	Ls	Mars-Sun dist (au)
PHObos window	25/03	600	24 x 25	28°-31.5°	~160°	17.5°	1.599
Phobos track (PhT), uncalibrated	25/03	298	298 x 1	15°-21°	~160°	17.5°	1.599

Special corrections

Single-pixel track:

The average phase angle is 20°, Phobos distance is about 190 km, with Mars on the background.
All spectra are acquired on Phobos.
Dark current file: fond1403.dg2
Gain = 2
Focal plane temperature = -77.4 °C
The Phobos track is contamined by Marsshine, and is not calibrated.
Location of pixels on Phobos is not accurately determined.

Image-cube:

The average phase angle is 30°, Phobos distance is about 220 km.
About 400 spectra are acquired on Phobos, the other 200 on the dark sky.
Dark current file: fond2103.dg3
Gain = 3
Focal plane temperature = -76.7 °C
A special processing is applied to register spectral channels (spatial convolution applied by program CorPho.for to minimize registration discrepancies). Registered/convolved data are provided in files PHOEVEN.RES and PHOODD.RES.
Four different coordinate files are provided for this session, to plot either maps or camera-view of the image cube. See PHO_COOR.LBL.
Observations are performed at gain 3, but are recalibrated: the uncertainty on gain 3 coefficients does not affect this session.

Files

	Telemetry file	Edited data (track)	Edited data (image-cube)	Calibrated data (image-cube)	Coordinates (image cube)
Data file	PHOB2503.DAT	PHTEVEN.EDT PHTODD.EDT	PHOEVEN.EDT PHOODD.EDT PHOEVEN.RES PHOODD.RES	PHOEVEN.CAL PHOODD.CAL	PHO_COOR.DAT PHO_SCOR.DAT PHO_SCRN.DAT PIXLOC.CTR
Label	RAW_DATA.LBL	PHT_EDT.LBL	PHO_EDT.LBL PHO_RES.LBL	PHO_CAL.LBL	PHO_COOR.LBL

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